A student measures the terminal potential difference `(V)` of a cell (of emf `epsilon` and internal resistance `r`) as a function of the current `(I)` flowing through it. The slope and intercept of the graph between `V` and `I`, then respectively, equal

Options

A. `- r and epsilon`
B. `r and - epsilon`
C. `- epsilon and r`
D. `epsilon and - r`

Answer

A

Explanation

`V=epsilon-Ir,y=c-mx`
`therefore` Slope `=-r`, internal resistance.
`V_(max)` = emf `epsilon`. This is intercept of the y-axis.
`therefore` Slope is negative
`because` I decreases as R increases.